Method cast

graphlite/src/types/casting.rs:97–143

ROADMAP v0.5.0 - Type casting for static analysis (see ROADMAP.md §7)

(from: &GqlType, to: &GqlType)

    /// Perform explicit type cast
    #[allow(dead_code)] // ROADMAP v0.5.0 - Type casting for static analysis (see ROADMAP.md §7)
    pub fn cast(from: &GqlType, to: &GqlType) -> TypeResult<CastOperation> {
        if !Self::can_cast(from, to) {
            return Err(TypeError::InvalidCast(
                format!("{:?}", from),
                format!("{:?}", to),
            ));
        }

        // Same type - no operation needed
        if from == to {
            return Ok(CastOperation::Identity);
        }

        match (from, to) {
            // Boolean casts
            (GqlType::Boolean, GqlType::String { .. }) => Ok(CastOperation::BooleanToString),
            (GqlType::Boolean, to_t) if to_t.is_numeric() => Ok(CastOperation::BooleanToNumeric),
            (GqlType::String { .. }, GqlType::Boolean) => Ok(CastOperation::StringToBoolean),
            (from_t, GqlType::Boolean) if from_t.is_numeric() => {
                Ok(CastOperation::NumericToBoolean)
            }

            // Numeric casts
            (from_t, to_t) if from_t.is_numeric() && to_t.is_numeric() => {
                Ok(CastOperation::NumericCast)
            }
            (from_t, GqlType::String { .. }) if from_t.is_numeric() => {
                Ok(CastOperation::NumericToString)
            }
            (GqlType::String { .. }, to_t) if to_t.is_numeric() => {
                Ok(CastOperation::StringToNumeric)
            }

            // Temporal casts
            (from_t, to_t) if from_t.is_temporal() && to_t.is_temporal() => {
                Ok(CastOperation::TemporalCast)
            }
            (GqlType::String { .. }, to_t) if to_t.is_temporal() => {
                Ok(CastOperation::StringToTemporal)
            }
            (from_t, GqlType::String { .. }) if from_t.is_temporal() => {
                Ok(CastOperation::TemporalToString)
            }

            _ => Ok(CastOperation::Custom),
        }
    }

    /// Check if a value satisfies IS TYPED predicate
    #[allow(dead_code)] // ROADMAP v0.5.0 - Type casting for static analysis (see ROADMAP.md §7)